Smoke and gas burning firebox



C. E. BETCHER.

SMOKE AND GAS BURNING FIREBOX.

APPLICATION min AUG.21, 191s.

STATE r rsi.

CHESTER E. BETCHER, 0F IVINNEAPOLS, MNNESOTA.

SMOKE AND GAS BURN 1N@ FIREBOX.

Leraars.

Specification of Letters Patent.

satelites api. s, resi.

Application filed August 21, 1918. Serial No. 250,724.

To all whom it may 'concern/.f o

Be it known that l, CHESTER E. Bn'rorrnu,

securing more yperfect combustion of fuel than is possible in furnaces which are now in common use, whether combustion is supported by air alone or by both air and steam. ln customary furnaces which are in use, only an imperfect combustion ofthe fuel is obtained because a large percentage of .the gaseous products pass off unconsinned.. The result of thisis that a large amount of lpotential heat is wasted and quantities of smoke and soot are discharged into the atmosphere with attendant injurious results. ln carrying out my invention, l provide the lire-box with means which cause the smoke and gases coming from the fuel to be subjected to a high degree of heat before they `are given an opportunity to escape through the chimney. l also provide means for preheating the air which is supplied to support the combustion of the gases and smoke. By the provision of these means, l secure a steady and uniform heat and almost complete combustion of the coinbustible. elements. rlhis results in a great saving of fuel and elimination of smoke.

rEhe full objects and advantages of my invention will appear in connection withr the detailed description thereof, and the novel features embodied in my invention are Vparticularly pointedy out in the claims.

rlihe accompanying drawings illustrate my invention applied to a boiler furnace, but it is to be understood that the invention is not limited to this type of furnace and may be employed to advantage in other types of furnaces.

Referring to the drawings which show my invention in one of the embodiments which it may assume, Figure 1 is a longitudinal section of a boiler furnace with my invention applied thereto. F ig. 2 is a view in cross section. Fig. 3 is a view on the line 3-3 of Fig. 2 looking downwardly.

ln the drawings, 10 designates a boiler which may be of the usual construction set in brick work 11 constituting the mainwalls of the furnace and having a stack 12. Underneath the rear portion of the boiler' is a combustion chamber 1e and underneath the front portieri ofthe boiler is a fire-box 16. The front of the fire-box is provided with a charging door 18 and at the bottom there is a grate 2O discharging into the main ash pit 22 in the usual manner. The grate iS operated by hand lever 21 and a connecting rod 23. Extending' downwardly at the rear end of the grate 20 is a transverse partition 24; which extends about halfway to the' bottom of the main ash pit. Above the rear end of the grate and spaced from the bottom of the fire-box is a wall member y 26 which `forms an essential feature of my invention. rhis wall'meinber is preferably molded in one piece from a mixture consistingk of substantially the following parts by measure: two parts of crushed burnt fire brick, one part of fresh fire clay, and one part of saw-dust. This mixture has no shrinkage during firing. rlhis wall member is moldedinto shape so that the rear portion thereof is curved to lit closely upon the boiler and leave no communication at this place between the fire-box and the combustion chamber'. rlfhe front of the wall member is of less height than the rear portion so as to be spaced from the boiler and said member is provided with a plurality of flues BO which extend downwardly from the top of the short portion and near the bottom of the wall are preferably turned rearwardly at 32so as to discharge behind the wall member. For large furnaces, this member may be molded directly into its place in the furnace and fired and burned therein. @n account of the non-shrinking character of the composition, the said memberremains securely supported in place. For smaller furnaces, the member may be molded outside of the furnace in one or more pieces and then placed in position in the furnace where it is supported by the brick walls. rlhe saw-dust soon burns out, leaving a porous structure which readily becomes highly heated. The gases and smoke in the lire-box pass through the fiues and during their )as sage are heated to a high temperature. he tops of the iiues 30 are provided with slides Set which may be pushed over the fines te partly close them when the full draft is not required. If desired, a small door 35 may be provided at the front of the furnace so y that the slides may be readily reached. Y The wall or flue member 26 is spaced at its lower end a short distance from'the front of the bridge Wall 36 which is inclined upwardly at 38 away from the member 26. The top 40 of the bridge wall is curved and spaced a short distance from the boiler so as toleave a passage 42 leading into the combustion chamber 14. At the rear of the grate 2O is a secondary grate 44 and underneath this grate is an auxiliary ash-pit separated from the main'ash-pit by the partition 24. The grate 44 is operated by a hand lever 45 and a connecting rod 47. The bottom of the auxiliary ash-pit consists of a pivoted plate 46, the rear end of which is weighted so that the plate is normally held in horizontal position with its rear end resting upon the sto p 48 and its front end abutting the partition 24. The front of the plate is provided with an arm to which is pivoted a rod 50 extending to the front of the furnace by means of which the contents of the auxiliary ash-pit may be dumped into the main aslrpit. A passageway or draft fiue 52 leads from the outside of the' furnace through bridge wall into the auxiliary ash-pit, a'damper 54 being provided to regulate the draft through the passageway. LThe bottom plate 46 closes the auxiliary ash-pit and causes the current of pre-heated air to pass up through the secondary grate to the rear of the wall member 26 so that the gases of combustion are dis-` charged directly into said current. The bot-- tom plate also prevents cold air from the front of the furnace passing` through the auxiliary ash-pit, which undesirable result would otherwise occur. The fresh air which is supplied through the passageway 52 is pre-heated by the hot walls of the furnace and then mingles with the hot gases and smoke which are compelled to pass through the flues 30, thus furnishing the' oxygen necessary to support combustion. Very satisfactory results are obtained in this way. Sometimes, however, it may be desirable to Y mix steam with the heated gases and for this purpose l have shown a steam `pipe 56 which discharges near the exit end of the fines. The position of the end of the pipe 56 is indicated in dotted lines in Fig. 1. In order that the condition of the furnace may be readily observed, I may provide a tube 5? containing a transparent disk of mica or 0' ass.

D The operation and advantages of my invention will be obvious from the foregoing description. Practically all of the' gases which are formed in the fire-box are forced to pass through the highly heated flues 30 and these very hot gases as they escape from the discharge end of the flues are mixed with preheated fresh air which causes almost complete combustion of the gases to occur. This results in saving a large percentage of the fuel and prevents the discharge of smoke from the chimney or stack. The provision of a non-shrinking flue member molded in place in the fire-box results in said member being verysecurely held in place Without danger of its falling down into the lire-box.

I claim:

l; A furnace comprising a fire-box, a wall member dividing said fire-box into front and rear compartments, said wall member being spacedabove the bottom of the fire-box and provided .with ues leading from said front compartment to said rear compartment, a main ash-pit below said front compartment, an auxiliary ash-pit below said rear compartment and means for supplying preheated air to said auxiliary ash-pit.

2. A furnace comprising a nre-box, front and rear grates in the bottom of said fires box, a wall member dividing said fire-box into front and rear compartments, said wall member being spaced above the line of separation of said grates and provided with lines leading from said front compartment to said rear compartment, a main ash pit below the front grate, an auxiliary ashpit below the rear grate,` means for supplying preheated air to said auxiliary ashpit, a pivoted plate constituting the bottom of said `auxiliary ashpit, and means `whereby said plate may be tilted to discharge the contents of said auxiliary ashpit into said main ashpit.

In testimony whereof I hereunto aHix my signature.

CHESTER E. BETCHER. 

